Analysis of polynitrophenols and hexyl by liquid chromatography-mass spectrometry using atmospheric pressure ionisation methods and a volatile ion-pairing reagent
In: Journal of Chromatography A, J. Chromatogr. A, Jg. 943 (2002) ; Nr. 1, S. 47-54
Zeitschriftenaufsatz / Fach: Chemie
An LC-MS method for the determination of picric acid (2,4,6- trinitrophenol), its reductive transformation products picramic acid (2-amino-4,6-dinitrophenol) and iso-picramic acid (4- amino-2,6-dinitrophenol) and hexyl (2,2',4,4',6,6'- hexanitrodiphenylamine) has been developed. The analytes were separated using ion-pairing chromatography with a volatile ion- pairing reagent suitable for subsequent MS detection. The performance of an atmospheric pressure chemical ionisation (APCI) and an electrospray ionisation (ESI) interface was compared. ESI-MS is more sensitive for the analytes, especially for hexyl and picric acid, APCI-MS delivered more fragments necessary for unequivocal identification. With LC-ESI-MS limits of detection using single ion monitoring (SIM) mode are 4 ng (iso-picramic acid), 800 pg (picramic acid), 400 pg (picric acid) and 90 pg (hexyl). For quantification, N-15-picric acid was used as an internal standard. Using this new method, the degradation of picric acid in soil was monitored in a laboratory study. Furthermore, the presence of picramic acid was for the first time verified in soil samples from a former ammunition plant. (C) 2002 Elsevier Science BY All rights reserved.